The present invention relates to a medical device.
More particularly, the invention relates to a medical device in the nature of a tube having a weighted tip or front end portion.
Still more specifically, the invention relates to a medical device of the kind used as catheter, feeding tube or the like.
The invention relates also to the tip--especially a bolus tip--and the composition of the same, which is used as part of the device. It will and should be understood, however, that certain details of the tip are themselves considered to be inventive, independently of the presence or absence of a tube.
There is a host of medical applications in which a tube must be inserted into and through a body orifice, usually to administer a flowable substance such as food or, as is becoming more prevalent, fluids which were heretofore administered by IV (i.e. intravenously).
In many instances, the insertion of such a tube is not possible without--or is at least facilitated by--the presence of a weighted tip or front end portion, generally known as a bolus tip. However, helpful and necessary as the presence of such a tip may be, it has created certain serious problems in the prior art.
One of these problems results from the relationship between tip and tube. The prior-art tips are of solid cross-section and the tube has one or more ports or openings rearwardly of the tip; the fluid exits through these openings. Because the tip is secured to the tube by means of a connector, the openings cannot be located directly adjacent its rear end; this means that there is a length of tube between the rear end of the tip and the outlet openings, in which some of the fluid can accumulate and stagnate (since there is no flow in this tube length). In many instances the nature of the fluid being administered through the tube is such that the fluid constitutes a nutrient medium for the growth of bacteria, and this is precisely what takes place in the "pocket" of tubing filled with the stagnant fluid. It goes without saying that this can be very dangerous, in view of the ever-present possibility that it may lead to serious infection in the patient who is being treated with the device.
Another problem resides in the composition of the prior-art tips themselves. Many of them are rigid and therefore present difficulties in connection with their introduction into a body orifice. More importantly, however, problems are experienced with the kinds of metals of which the prior-art tips are made which are, in fact, flexible to some degree. In order to achieve such flexibility, the metal is used in particulate form; it is even known to use mercury. The metal is then either contained in this form in a lumen of the tip cover, or is simply encased by such a cover (e.g. in the form of a sheath of synthetic plastic material). A problem with this type of construction is that in practice it has been found to leak or spill. That is to say, it has been found that in the prior art there is a tendency for the particulate or fluent metal to escape from its confinement. Should this occur inside a patient, the very least that would happen is the undesirable contamination of a given body region with the spilled metal. Depending upon the kind of metal involved, however, there may also be a greater or lesser toxicity (e.g. mercury) with consequent endangerment of the patient's health.
Also, the prior-art devices require connectors which join the tip to the tube. Aside from the fact that the use of such connectors increases the cost of these devices, since it represents the use of an additional component and the operating step required to install the same, there is the further problem that each such connector potentially represents a situs at which metal spillage may occur.
The prior-art devices are thus clearly in need of improvement which, however, has not heretofore been forthcoming.